Just a quick note about only being able to feel the incoming attack from a fellow Aikido student. This is a fairly common thing that will come up a lot.

Aikido students are trained in the ability to have the intention and projection of a real attack while physically stopping short. When practicing with your friends, there is no real intention or projection behind his punch unless he is actually going to slug you.

Things like this will happen often with beginners and the untrained. Over time you will improve your ability to flood your awareness through your partner's body and feel his intentions even if they are weak and scattered.